Here at The Lighthouse we have been testing and reviewing a selection of the latest retro-fit LED lamps for a new residential project. Retro-fit LED lamps are used to replace the equivalent more energy intensive tungsten equivalents which prevailed prior to the development of LED light sources.
There are a multitude of retro-fit LED lamps available and as the title of this post suggests, some are good, some are bad and some produce downright 'ugly' light. So how do you know which lamps to choose? There is only one way to do this - get a sample of each and test them! You will soon find out that the colour temperature [warm white, cool white etc.] labelled on the lamp only gives an indication of the colour appearance of the light - comparing two lamps side by side can produce staggeringly different results [see the photo below for an example]. Some lamps appear to produce pinkish light, others appear cooler than the 3000K quoted. Some of this is the fault of the way in which colour temperature is quantified but sometimes its simply bad quality light being produced.
Lamp quality is not just about colour temperature though, the quality of the light 'beam' is also important - this can easily be checked by aiming the light at a white surface and seeing how 'clean' the distribution of light is. Often lamps will be available in several beam options [narrow, medium, wide etc.] but some narrow beams really are narrow whilst others are less controlled. This can make a real difference if you are using light to add drama in an environment.
The colour rendering ability of the lamps also matters - that is, how the light makes colours appear - this is very important in the retail world but also matters in a residential context. Some retro-fit LED lamps have appalling colour rendering abilities and can make skin tones look pallid and grey - all very depressing!
We often recommend that the dimming of lamps be considered in residential [and other] applications so that the lighting levels can be adjusted to suit the varying activities which take place in the home. With tungsten lamps [ones with lit filaments] this was relatively straightforward and on the whole smooth dimming of lamps to low levels was achievable. With LED lamps this is a real headache and the dimming ability of the lamps and their compatibility with the dimming equipment itself needs to be thoroughly checked. It is common for retro-fit lamps to suffer from instability [flicker etc.] at low light levels or not to dim smoothly. The only way to be sure is to test the proposed lamps with the proposed dimmer.
So, if you are thinking of replacing all of the energy hungry low voltage lamps in your home with new LED lamps make sure you do your homework or seek advice. When it comes to LED lamps things are not quite as straightforward as they can quite often appear.